Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Other comprehensive income (loss) before reclassifications			$ 1,209	$ 910
Amounts reclassified from accumulated OCI			(1,430)	(1,385)
Net other comprehensive income (loss)			(221)	(656)
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance			2,766	3,529
Net other comprehensive income (loss)	$ 240	$ 566	(221)	(656)
Accumulated other comprehensive income, ending balance	2,545	2,873	2,545	2,873
Foreign Currency Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance			(1,800)	(1,964)
Other comprehensive income (loss) before reclassifications			367	160
Amounts reclassified from accumulated OCI			0	0
Net other comprehensive income (loss)			367	(22)
Accumulated other comprehensive income, ending balance	(1,433)	(1,986)	(1,433)	(1,986)
Net Unrealized Gains (Losses) on Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance			(90)	45
Other comprehensive income (loss) before reclassifications			(25)	(152)
Amounts reclassified from accumulated OCI			7	7
Net other comprehensive income (loss)			(18)	(145)
Accumulated other comprehensive income, ending balance	(108)	(100)	(108)	(100)
Net Unrealized Gains (Losses) on Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance			(1,998)	(1,422)
Other comprehensive income (loss) before reclassifications			867	(885)
Amounts reclassified from accumulated OCI			35	85
Net other comprehensive income (loss)			902	(824)
Accumulated other comprehensive income, ending balance	(1,096)	(2,246)	(1,096)	(2,246)
Defined Benefit Postretirement Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated other comprehensive income, beginning balance			6,654	6,870
Other comprehensive income (loss) before reclassifications			0	1,787
Amounts reclassified from accumulated OCI			(1,472)	(1,477)
Net other comprehensive income (loss)			(1,472)	335
Accumulated other comprehensive income, ending balance	$ 5,182	$ 7,205	$ 5,182	7,205
Reclassification out of Accumulated Other Comprehensive Income [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Amounts reclassified from accumulated OCI				(181)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Foreign Currency Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Amounts reclassified from accumulated OCI				(182)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Unrealized Gains (Losses) on Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Amounts reclassified from accumulated OCI				0
Reclassification out of Accumulated Other Comprehensive Income [Member] | Net Unrealized Gains (Losses) on Derivative Instruments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Amounts reclassified from accumulated OCI				(24)
Reclassification out of Accumulated Other Comprehensive Income [Member] | Defined Benefit Postretirement Plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Amounts reclassified from accumulated OCI				$ 25